Merge commit 'v2.6.26' into bkl-removal

13 files changed, 204 insertions, 194 deletions

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 41f84c92094f..10bfb466e068 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -2788,7 +2788,7 @@ static int ocfs2_merge_rec_right(struct inode *inode,
         BUG_ON(index >= le16_to_cpu(el->l_next_free_rec));
         left_rec = &el->l_recs[index];
 
-        if (index == le16_to_cpu(el->l_next_free_rec - 1) &&
+        if (index == le16_to_cpu(el->l_next_free_rec) - 1 &&
             le16_to_cpu(el->l_next_free_rec) == le16_to_cpu(el->l_count)) {
                 /* we meet with a cross extent block merge. */
                 ret = ocfs2_get_right_path(inode, left_path, &right_path);
@@ -2802,7 +2802,7 @@ static int ocfs2_merge_rec_right(struct inode *inode,
                 BUG_ON(next_free <= 0);
                 right_rec = &right_el->l_recs[0];
                 if (ocfs2_is_empty_extent(right_rec)) {
-                        BUG_ON(le16_to_cpu(next_free) <= 1);
+                        BUG_ON(next_free <= 1);
                         right_rec = &right_el->l_recs[1];
                 }
 
diff --git a/fs/ocfs2/cluster/nodemanager.c b/fs/ocfs2/cluster/nodemanager.c
index cf9401e8cd0b..cfdb08b484ed 100644
--- a/fs/ocfs2/cluster/nodemanager.c
+++ b/fs/ocfs2/cluster/nodemanager.c
@@ -21,7 +21,6 @@
 
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/sysctl.h>
 #include <linux/configfs.h>
 
 #include "tcp.h"
@@ -36,65 +35,6 @@
  * cluster references throughout where nodes are looked up */
 struct o2nm_cluster *o2nm_single_cluster = NULL;
 
-#define OCFS2_MAX_HB_CTL_PATH 256
-static char ocfs2_hb_ctl_path[OCFS2_MAX_HB_CTL_PATH] = "/sbin/ocfs2_hb_ctl";
-
-static ctl_table ocfs2_nm_table[] = {
-        {
-                .ctl_name       = 1,
-                .procname       = "hb_ctl_path",
-                .data           = ocfs2_hb_ctl_path,
-                .maxlen         = OCFS2_MAX_HB_CTL_PATH,
-                .mode           = 0644,
-                .proc_handler   = &proc_dostring,
-                .strategy       = &sysctl_string,
-        },
-        { .ctl_name = 0 }
-};
-
-static ctl_table ocfs2_mod_table[] = {
-        {
-                .ctl_name       = FS_OCFS2_NM,
-                .procname       = "nm",
-                .data           = NULL,
-                .maxlen         = 0,
-                .mode           = 0555,
-                .child          = ocfs2_nm_table
-        },
-        { .ctl_name = 0}
-};
-
-static ctl_table ocfs2_kern_table[] = {
-        {
-                .ctl_name       = FS_OCFS2,
-                .procname       = "ocfs2",
-                .data           = NULL,
-                .maxlen         = 0,
-                .mode           = 0555,
-                .child          = ocfs2_mod_table
-        },
-        { .ctl_name = 0}
-};
-
-static ctl_table ocfs2_root_table[] = {
-        {
-                .ctl_name       = CTL_FS,
-                .procname       = "fs",
-                .data           = NULL,
-                .maxlen         = 0,
-                .mode           = 0555,
-                .child          = ocfs2_kern_table
-        },
-        { .ctl_name = 0 }
-};
-
-static struct ctl_table_header *ocfs2_table_header = NULL;
-
-const char *o2nm_get_hb_ctl_path(void)
-{
-        return ocfs2_hb_ctl_path;
-}
-EXPORT_SYMBOL_GPL(o2nm_get_hb_ctl_path);
 
 struct o2nm_node *o2nm_get_node_by_num(u8 node_num)
 {
@@ -941,9 +881,6 @@ void o2nm_undepend_this_node(void)
 
 static void __exit exit_o2nm(void)
 {
-        if (ocfs2_table_header)
-                unregister_sysctl_table(ocfs2_table_header);
-
         /* XXX sync with hb callbacks and shut down hb? */
         o2net_unregister_hb_callbacks();
         configfs_unregister_subsystem(&o2nm_cluster_group.cs_subsys);
@@ -964,16 +901,9 @@ static int __init init_o2nm(void)
         if (ret)
                 goto out;
 
-        ocfs2_table_header = register_sysctl_table(ocfs2_root_table);
-        if (!ocfs2_table_header) {
-                printk(KERN_ERR "nodemanager: unable to register sysctl\n");
-                ret = -ENOMEM; /* or something. */
-                goto out_o2net;
-        }
-
         ret = o2net_register_hb_callbacks();
         if (ret)
-                goto out_sysctl;
+                goto out_o2net;
 
         config_group_init(&o2nm_cluster_group.cs_subsys.su_group);
         mutex_init(&o2nm_cluster_group.cs_subsys.su_mutex);
@@ -990,8 +920,6 @@ static int __init init_o2nm(void)
         configfs_unregister_subsystem(&o2nm_cluster_group.cs_subsys);
 out_callbacks:
         o2net_unregister_hb_callbacks();
-out_sysctl:
-        unregister_sysctl_table(ocfs2_table_header);
 out_o2net:
         o2net_exit();
 out:
diff --git a/fs/ocfs2/cluster/nodemanager.h b/fs/ocfs2/cluster/nodemanager.h
index 7c860361b8dd..c992ea0da4ad 100644
--- a/fs/ocfs2/cluster/nodemanager.h
+++ b/fs/ocfs2/cluster/nodemanager.h
@@ -33,10 +33,6 @@
 #include <linux/configfs.h>
 #include <linux/rbtree.h>
 
-#define FS_OCFS2_NM             1
-
-const char *o2nm_get_hb_ctl_path(void);
-
 struct o2nm_node {
         spinlock_t              nd_lock;
         struct config_item      nd_item;
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
index 1e44ad14881a..a27d61581bd6 100644
--- a/fs/ocfs2/cluster/tcp.c
+++ b/fs/ocfs2/cluster/tcp.c
@@ -142,53 +142,43 @@ static void o2net_idle_timer(unsigned long data);
 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
 
-static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
-                           u32 msgkey, struct task_struct *task, u8 node)
-{
 #ifdef CONFIG_DEBUG_FS
+void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
+                    u32 msgkey, struct task_struct *task, u8 node)
+{
         INIT_LIST_HEAD(&nst->st_net_debug_item);
         nst->st_task = task;
         nst->st_msg_type = msgtype;
         nst->st_msg_key = msgkey;
         nst->st_node = node;
-#endif
 }
 
-static void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
+void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
 {
-#ifdef CONFIG_DEBUG_FS
         do_gettimeofday(&nst->st_sock_time);
-#endif
 }
 
-static void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
+void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
 {
-#ifdef CONFIG_DEBUG_FS
         do_gettimeofday(&nst->st_send_time);
-#endif
 }
 
-static void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
+void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
 {
-#ifdef CONFIG_DEBUG_FS
         do_gettimeofday(&nst->st_status_time);
-#endif
 }
 
-static void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
+void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
                                          struct o2net_sock_container *sc)
 {
-#ifdef CONFIG_DEBUG_FS
         nst->st_sc = sc;
-#endif
 }
 
-static void o2net_set_nst_msg_id(struct o2net_send_tracking *nst, u32 msg_id)
+void o2net_set_nst_msg_id(struct o2net_send_tracking *nst, u32 msg_id)
 {
-#ifdef CONFIG_DEBUG_FS
         nst->st_id = msg_id;
-#endif
 }
+#endif /* CONFIG_DEBUG_FS */
 
 static inline int o2net_reconnect_delay(void)
 {
diff --git a/fs/ocfs2/cluster/tcp.h b/fs/ocfs2/cluster/tcp.h
index a705d5d19036..fd6179eb26d4 100644
--- a/fs/ocfs2/cluster/tcp.h
+++ b/fs/ocfs2/cluster/tcp.h
@@ -128,23 +128,23 @@ void o2net_debug_del_nst(struct o2net_send_tracking *nst);
 void o2net_debug_add_sc(struct o2net_sock_container *sc);
 void o2net_debug_del_sc(struct o2net_sock_container *sc);
 #else
-static int o2net_debugfs_init(void)
+static inline int o2net_debugfs_init(void)
 {
         return 0;
 }
-static void o2net_debugfs_exit(void)
+static inline void o2net_debugfs_exit(void)
 {
 }
-static void o2net_debug_add_nst(struct o2net_send_tracking *nst)
+static inline void o2net_debug_add_nst(struct o2net_send_tracking *nst)
 {
 }
-static void o2net_debug_del_nst(struct o2net_send_tracking *nst)
+static inline void o2net_debug_del_nst(struct o2net_send_tracking *nst)
 {
 }
-static void o2net_debug_add_sc(struct o2net_sock_container *sc)
+static inline void o2net_debug_add_sc(struct o2net_sock_container *sc)
 {
 }
-static void o2net_debug_del_sc(struct o2net_sock_container *sc)
+static inline void o2net_debug_del_sc(struct o2net_sock_container *sc)
 {
 }
 #endif  /* CONFIG_DEBUG_FS */
diff --git a/fs/ocfs2/cluster/tcp_internal.h b/fs/ocfs2/cluster/tcp_internal.h
index 8d58cfe410b1..18307ff81b77 100644
--- a/fs/ocfs2/cluster/tcp_internal.h
+++ b/fs/ocfs2/cluster/tcp_internal.h
@@ -224,10 +224,42 @@ struct o2net_send_tracking {
         struct timeval                  st_send_time;
         struct timeval                  st_status_time;
 };
+
+void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
+                    u32 msgkey, struct task_struct *task, u8 node);
+void o2net_set_nst_sock_time(struct o2net_send_tracking *nst);
+void o2net_set_nst_send_time(struct o2net_send_tracking *nst);
+void o2net_set_nst_status_time(struct o2net_send_tracking *nst);
+void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
+                                  struct o2net_sock_container *sc);
+void o2net_set_nst_msg_id(struct o2net_send_tracking *nst, u32 msg_id);
+
 #else
 struct o2net_send_tracking {
         u32     dummy;
 };
+
+static inline void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
+                                  u32 msgkey, struct task_struct *task, u8 node)
+{
+}
+static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
+{
+}
+static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
+{
+}
+static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
+{
+}
+static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
+                                                struct o2net_sock_container *sc)
+{
+}
+static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst,
+                                        u32 msg_id)
+{
+}
 #endif  /* CONFIG_DEBUG_FS */
 
 #endif /* O2CLUSTER_TCP_INTERNAL_H */
diff --git a/fs/ocfs2/dlm/dlmdebug.h b/fs/ocfs2/dlm/dlmdebug.h
index d34a62a3a625..8c686d22f9c7 100644
--- a/fs/ocfs2/dlm/dlmdebug.h
+++ b/fs/ocfs2/dlm/dlmdebug.h
@@ -60,25 +60,25 @@ void dlm_destroy_debugfs_root(void);
 
 #else
 
-static int dlm_debug_init(struct dlm_ctxt *dlm)
+static inline int dlm_debug_init(struct dlm_ctxt *dlm)
 {
         return 0;
 }
-static void dlm_debug_shutdown(struct dlm_ctxt *dlm)
+static inline void dlm_debug_shutdown(struct dlm_ctxt *dlm)
 {
 }
-static int dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
+static inline int dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
 {
         return 0;
 }
-static void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm)
+static inline void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm)
 {
 }
-static int dlm_create_debugfs_root(void)
+static inline int dlm_create_debugfs_root(void)
 {
         return 0;
 }
-static void dlm_destroy_debugfs_root(void)
+static inline void dlm_destroy_debugfs_root(void)
 {
 }
 
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index efc015c6128a..44f87caf3683 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -606,7 +606,9 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
 
         res->last_used = 0;
 
+        spin_lock(&dlm->spinlock);
         list_add_tail(&res->tracking, &dlm->tracking_list);
+        spin_unlock(&dlm->spinlock);
 
         memset(res->lvb, 0, DLM_LVB_LEN);
         memset(res->refmap, 0, sizeof(res->refmap));
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 394d25a131a5..80e20d9f2780 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -1554,8 +1554,8 @@ out:
  */
 int ocfs2_file_lock(struct file *file, int ex, int trylock)
 {
-        int ret, level = ex ? LKM_EXMODE : LKM_PRMODE;
-        unsigned int lkm_flags = trylock ? LKM_NOQUEUE : 0;
+        int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+        unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0;
         unsigned long flags;
         struct ocfs2_file_private *fp = file->private_data;
         struct ocfs2_lock_res *lockres = &fp->fp_flock;
@@ -1582,7 +1582,7 @@ int ocfs2_file_lock(struct file *file, int ex, int trylock)
                  * Get the lock at NLMODE to start - that way we
                  * can cancel the upconvert request if need be.
                  */
-                ret = ocfs2_lock_create(osb, lockres, LKM_NLMODE, 0);
+                ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, 0);
                 if (ret < 0) {
                         mlog_errno(ret);
                         goto out;
@@ -1597,7 +1597,7 @@ int ocfs2_file_lock(struct file *file, int ex, int trylock)
         }
 
         lockres->l_action = OCFS2_AST_CONVERT;
-        lkm_flags |= LKM_CONVERT;
+        lkm_flags |= DLM_LKF_CONVERT;
         lockres->l_requested = level;
         lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
 
@@ -1664,7 +1664,7 @@ void ocfs2_file_unlock(struct file *file)
         if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
                 return;
 
-        if (lockres->l_level == LKM_NLMODE)
+        if (lockres->l_level == DLM_LOCK_NL)
                 return;
 
         mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
@@ -1678,11 +1678,11 @@ void ocfs2_file_unlock(struct file *file)
         lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
         lockres->l_blocking = DLM_LOCK_EX;
 
-        gen = ocfs2_prepare_downconvert(lockres, LKM_NLMODE);
+        gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL);
         lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
         spin_unlock_irqrestore(&lockres->l_lock, flags);
 
-        ret = ocfs2_downconvert_lock(osb, lockres, LKM_NLMODE, 0, gen);
+        ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, 0, gen);
         if (ret) {
                 mlog_errno(ret);
                 return;
diff --git a/fs/ocfs2/stack_o2cb.c b/fs/ocfs2/stack_o2cb.c
index bbd1667aa7d3..fcd120f1493a 100644
--- a/fs/ocfs2/stack_o2cb.c
+++ b/fs/ocfs2/stack_o2cb.c
@@ -317,8 +317,7 @@ out:
         return rc;
 }
 
-static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn,
-                                   int hangup_pending)
+static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn)
 {
         struct dlm_ctxt *dlm = conn->cc_lockspace;
         struct o2dlm_private *priv = conn->cc_private;
@@ -333,43 +332,6 @@ static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn,
         return 0;
 }
 
-static void o2hb_stop(const char *group)
-{
-        int ret;
-        char *argv[5], *envp[3];
-
-        argv[0] = (char *)o2nm_get_hb_ctl_path();
-        argv[1] = "-K";
-        argv[2] = "-u";
-        argv[3] = (char *)group;
-        argv[4] = NULL;
-
-        mlog(0, "Run: %s %s %s %s\n", argv[0], argv[1], argv[2], argv[3]);
-
-        /* minimal command environment taken from cpu_run_sbin_hotplug */
-        envp[0] = "HOME=/";
-        envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
-        envp[2] = NULL;
-
-        ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
-        if (ret < 0)
-                mlog_errno(ret);
-}
-
-/*
- * Hangup is a hack for tools compatibility.  Older ocfs2-tools software
- * expects the filesystem to call "ocfs2_hb_ctl" during unmount.  This
- * happens regardless of whether the DLM got started, so we can't do it
- * in ocfs2_cluster_disconnect().  We bring the o2hb_stop() function into
- * the glue and provide a "hangup" API for super.c to call.
- *
- * Other stacks will eventually provide a NULL ->hangup() pointer.
- */
-static void o2cb_cluster_hangup(const char *group, int grouplen)
-{
-        o2hb_stop(group);
-}
-
 static int o2cb_cluster_this_node(unsigned int *node)
 {
         int node_num;
@@ -388,7 +350,6 @@ static int o2cb_cluster_this_node(unsigned int *node)
 static struct ocfs2_stack_operations o2cb_stack_ops = {
         .connect        = o2cb_cluster_connect,
         .disconnect     = o2cb_cluster_disconnect,
-        .hangup         = o2cb_cluster_hangup,
         .this_node      = o2cb_cluster_this_node,
         .dlm_lock       = o2cb_dlm_lock,
         .dlm_unlock     = o2cb_dlm_unlock,
diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index cd120011104d..bd7e0f3acfc7 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -62,7 +62,7 @@
  * negotiated by the client.  The client negotiates based on the maximum
  * version advertised in /sys/fs/ocfs2/max_locking_protocol.  The major
  * number from the "SETV" message must match
- * user_stack.sp_proto->lp_max_version.pv_major, and the minor number
+ * ocfs2_user_plugin.sp_proto->lp_max_version.pv_major, and the minor number
  * must be less than or equal to ...->lp_max_version.pv_minor.
  *
  * Once this information has been set, mounts will be allowed.  From this
@@ -154,7 +154,7 @@ union ocfs2_control_message {
         struct ocfs2_control_message_down       u_down;
 };
 
-static struct ocfs2_stack_plugin user_stack;
+static struct ocfs2_stack_plugin ocfs2_user_plugin;
 
 static atomic_t ocfs2_control_opened;
 static int ocfs2_control_this_node = -1;
@@ -400,7 +400,7 @@ static int ocfs2_control_do_setversion_msg(struct file *file,
         char *ptr = NULL;
         struct ocfs2_control_private *p = file->private_data;
         struct ocfs2_protocol_version *max =
-                &user_stack.sp_proto->lp_max_version;
+                &ocfs2_user_plugin.sp_proto->lp_max_version;
 
         if (ocfs2_control_get_handshake_state(file) !=
             OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
@@ -683,7 +683,7 @@ static void fsdlm_lock_ast_wrapper(void *astarg)
         struct dlm_lksb *lksb = fsdlm_astarg_to_lksb(astarg);
         int status = lksb->sb_status;
 
-        BUG_ON(user_stack.sp_proto == NULL);
+        BUG_ON(ocfs2_user_plugin.sp_proto == NULL);
 
         /*
          * For now we're punting on the issue of other non-standard errors
@@ -696,16 +696,16 @@ static void fsdlm_lock_ast_wrapper(void *astarg)
          */
 
         if (status == -DLM_EUNLOCK || status == -DLM_ECANCEL)
-                user_stack.sp_proto->lp_unlock_ast(astarg, 0);
+                ocfs2_user_plugin.sp_proto->lp_unlock_ast(astarg, 0);
         else
-                user_stack.sp_proto->lp_lock_ast(astarg);
+                ocfs2_user_plugin.sp_proto->lp_lock_ast(astarg);
 }
 
 static void fsdlm_blocking_ast_wrapper(void *astarg, int level)
 {
-        BUG_ON(user_stack.sp_proto == NULL);
+        BUG_ON(ocfs2_user_plugin.sp_proto == NULL);
 
-        user_stack.sp_proto->lp_blocking_ast(astarg, level);
+        ocfs2_user_plugin.sp_proto->lp_blocking_ast(astarg, level);
 }
 
 static int user_dlm_lock(struct ocfs2_cluster_connection *conn,
@@ -819,8 +819,7 @@ out:
         return rc;
 }
 
-static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn,
-                                   int hangup_pending)
+static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
 {
         dlm_release_lockspace(conn->cc_lockspace, 2);
         conn->cc_lockspace = NULL;
@@ -841,7 +840,7 @@ static int user_cluster_this_node(unsigned int *this_node)
         return 0;
 }
 
-static struct ocfs2_stack_operations user_stack_ops = {
+static struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
         .connect        = user_cluster_connect,
         .disconnect     = user_cluster_disconnect,
         .this_node      = user_cluster_this_node,
@@ -852,20 +851,20 @@ static struct ocfs2_stack_operations user_stack_ops = {
         .dump_lksb      = user_dlm_dump_lksb,
 };
 
-static struct ocfs2_stack_plugin user_stack = {
+static struct ocfs2_stack_plugin ocfs2_user_plugin = {
         .sp_name        = "user",
-        .sp_ops         = &user_stack_ops,
+        .sp_ops         = &ocfs2_user_plugin_ops,
         .sp_owner       = THIS_MODULE,
 };
 
 
-static int __init user_stack_init(void)
+static int __init ocfs2_user_plugin_init(void)
 {
         int rc;
 
         rc = ocfs2_control_init();
         if (!rc) {
-                rc = ocfs2_stack_glue_register(&user_stack);
+                rc = ocfs2_stack_glue_register(&ocfs2_user_plugin);
                 if (rc)
                         ocfs2_control_exit();
         }
@@ -873,14 +872,14 @@ static int __init user_stack_init(void)
         return rc;
 }
 
-static void __exit user_stack_exit(void)
+static void __exit ocfs2_user_plugin_exit(void)
 {
-        ocfs2_stack_glue_unregister(&user_stack);
+        ocfs2_stack_glue_unregister(&ocfs2_user_plugin);
         ocfs2_control_exit();
 }
 
 MODULE_AUTHOR("Oracle");
 MODULE_DESCRIPTION("ocfs2 driver for userspace cluster stacks");
 MODULE_LICENSE("GPL");
-module_init(user_stack_init);
-module_exit(user_stack_exit);
+module_init(ocfs2_user_plugin_init);
+module_exit(ocfs2_user_plugin_exit);
diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c
index 119f60cea9cc..10e149ae5e3a 100644
--- a/fs/ocfs2/stackglue.c
+++ b/fs/ocfs2/stackglue.c
@@ -26,6 +26,7 @@
 #include <linux/fs.h>
 #include <linux/kobject.h>
 #include <linux/sysfs.h>
+#include <linux/sysctl.h>
 
 #include "ocfs2_fs.h"
 
@@ -33,11 +34,13 @@
 
 #define OCFS2_STACK_PLUGIN_O2CB         "o2cb"
 #define OCFS2_STACK_PLUGIN_USER         "user"
+#define OCFS2_MAX_HB_CTL_PATH           256
 
 static struct ocfs2_locking_protocol *lproto;
 static DEFINE_SPINLOCK(ocfs2_stack_lock);
 static LIST_HEAD(ocfs2_stack_list);
 static char cluster_stack_name[OCFS2_STACK_LABEL_LEN + 1];
+static char ocfs2_hb_ctl_path[OCFS2_MAX_HB_CTL_PATH] = "/sbin/ocfs2_hb_ctl";
 
 /*
  * The stack currently in use.  If not null, active_stack->sp_count > 0,
@@ -349,7 +352,7 @@ int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
 
         BUG_ON(conn == NULL);
 
-        ret = active_stack->sp_ops->disconnect(conn, hangup_pending);
+        ret = active_stack->sp_ops->disconnect(conn);
 
         /* XXX Should we free it anyway? */
         if (!ret) {
@@ -362,13 +365,48 @@ int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
 }
 EXPORT_SYMBOL_GPL(ocfs2_cluster_disconnect);
 
+/*
+ * Leave the group for this filesystem.  This is executed by a userspace
+ * program (stored in ocfs2_hb_ctl_path).
+ */
+static void ocfs2_leave_group(const char *group)
+{
+        int ret;
+        char *argv[5], *envp[3];
+
+        argv[0] = ocfs2_hb_ctl_path;
+        argv[1] = "-K";
+        argv[2] = "-u";
+        argv[3] = (char *)group;
+        argv[4] = NULL;
+
+        /* minimal command environment taken from cpu_run_sbin_hotplug */
+        envp[0] = "HOME=/";
+        envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
+        envp[2] = NULL;
+
+        ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+        if (ret < 0) {
+                printk(KERN_ERR
+                       "ocfs2: Error %d running user helper "
+                       "\"%s %s %s %s\"\n",
+                       ret, argv[0], argv[1], argv[2], argv[3]);
+        }
+}
+
+/*
+ * Hangup is a required post-umount.  ocfs2-tools software expects the
+ * filesystem to call "ocfs2_hb_ctl" during unmount.  This happens
+ * regardless of whether the DLM got started, so we can't do it
+ * in ocfs2_cluster_disconnect().  The ocfs2_leave_group() function does
+ * the actual work.
+ */
 void ocfs2_cluster_hangup(const char *group, int grouplen)
 {
         BUG_ON(group == NULL);
         BUG_ON(group[grouplen] != '\0');
 
-        if (active_stack->sp_ops->hangup)
-                active_stack->sp_ops->hangup(group, grouplen);
+        ocfs2_leave_group(group);
 
         /* cluster_disconnect() was called with hangup_pending==1 */
         ocfs2_stack_driver_put();
@@ -548,10 +586,83 @@ error:
         return ret;
 }
 
+/*
+ * Sysctl bits
+ *
+ * The sysctl lives at /proc/sys/fs/ocfs2/nm/hb_ctl_path.  The 'nm' doesn't
+ * make as much sense in a multiple cluster stack world, but it's safer
+ * and easier to preserve the name.
+ */
+
+#define FS_OCFS2_NM             1
+
+static ctl_table ocfs2_nm_table[] = {
+        {
+                .ctl_name       = 1,
+                .procname       = "hb_ctl_path",
+                .data           = ocfs2_hb_ctl_path,
+                .maxlen         = OCFS2_MAX_HB_CTL_PATH,
+                .mode           = 0644,
+                .proc_handler   = &proc_dostring,
+                .strategy       = &sysctl_string,
+        },
+        { .ctl_name = 0 }
+};
+
+static ctl_table ocfs2_mod_table[] = {
+        {
+                .ctl_name       = FS_OCFS2_NM,
+                .procname       = "nm",
+                .data           = NULL,
+                .maxlen         = 0,
+                .mode           = 0555,
+                .child          = ocfs2_nm_table
+        },
+        { .ctl_name = 0}
+};
+
+static ctl_table ocfs2_kern_table[] = {
+        {
+                .ctl_name       = FS_OCFS2,
+                .procname       = "ocfs2",
+                .data           = NULL,
+                .maxlen         = 0,
+                .mode           = 0555,
+                .child          = ocfs2_mod_table
+        },
+        { .ctl_name = 0}
+};
+
+static ctl_table ocfs2_root_table[] = {
+        {
+                .ctl_name       = CTL_FS,
+                .procname       = "fs",
+                .data           = NULL,
+                .maxlen         = 0,
+                .mode           = 0555,
+                .child          = ocfs2_kern_table
+        },
+        { .ctl_name = 0 }
+};
+
+static struct ctl_table_header *ocfs2_table_header = NULL;
+
+
+/*
+ * Initialization
+ */
+
 static int __init ocfs2_stack_glue_init(void)
 {
         strcpy(cluster_stack_name, OCFS2_STACK_PLUGIN_O2CB);
 
+        ocfs2_table_header = register_sysctl_table(ocfs2_root_table);
+        if (!ocfs2_table_header) {
+                printk(KERN_ERR
+                       "ocfs2 stack glue: unable to register sysctl\n");
+                return -ENOMEM; /* or something. */
+        }
+
         return ocfs2_sysfs_init();
 }
 
@@ -559,6 +670,8 @@ static void __exit ocfs2_stack_glue_exit(void)
 {
         lproto = NULL;
         ocfs2_sysfs_exit();
+        if (ocfs2_table_header)
+                unregister_sysctl_table(ocfs2_table_header);
 }
 
 MODULE_AUTHOR("Oracle");
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
index 005e4f170e0f..db56281dd1be 100644
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -134,22 +134,10 @@ struct ocfs2_stack_operations {
          * be freed.  Thus, a stack must not return from ->disconnect()
          * until it will no longer reference the conn pointer.
          *
-         * If hangup_pending is zero, ocfs2_cluster_disconnect() will also
-         * be dropping the reference on the module.
+         * Once this call returns, the stack glue will be dropping this
+         * connection's reference on the module.
          */
-        int (*disconnect)(struct ocfs2_cluster_connection *conn,
-                          int hangup_pending);
-
-        /*
-         * ocfs2_cluster_hangup() exists for compatibility with older
-         * ocfs2 tools.  Only the classic stack really needs it.  As such
-         * ->hangup() is not required of all stacks.  See the comment by
-         * ocfs2_cluster_hangup() for more details.
-         *
-         * Note that ocfs2_cluster_hangup() can only be called if
-         * hangup_pending was passed to ocfs2_cluster_disconnect().
-         */
-        void (*hangup)(const char *group, int grouplen);
+        int (*disconnect)(struct ocfs2_cluster_connection *conn);
 
         /*
          * ->this_node() returns the cluster's unique identifier for the
@@ -258,4 +246,5 @@ void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto)
 /* Used by stack plugins */
 int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
 void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
+
 #endif  /* STACKGLUE_H */